EMMA Software Quick Start Guide

Transcription

1 EMMA QUICK START GUIDE EMMA Software Quick Start Guide MAN Delsys Incorporated 1

2 TABLE OF CONTENTS Section I: Introduction to EMMA Software 1. Biomechanical Model 2. Sensor Placement Guidelines 3. Angle Determinations 4. Guidelines for Data Collection Section II: EMMA Data Acquisition & Analysis 1. Test Configuration 2. Data Collection 3. Data Visualization & Analysis 4. Data Import & Export This document is designed to guide users through data collection and analysis using the EMMA software package with Trigno IM sensors. This serves as a companion user guide for the EMMA software only. Please refer to the Trigno Wireless EMG System manual (MAN-012) for all important hardware information, such as intended use, indications for use, warnings, precautions and overall safety opening EMMA, please ensure that you have the Trigno Control Utility open, and that your Trigno IM sensors are paired and calibrated. For more information, please refer to the Delsys SDK User Guide (MAN-025). DELSYS 2

3 Introduction to EMMA Software SECTION I ❶Biomechanical Model The EMMA software contains a skeletal model whose segments are driven by the orientations reported by Trigno IM sensors in the locations listed below. The model is displayed graphically by an on-screen avatar and can estimate joint angles based on the orientation estimates provided by the sensors. List of segments represented in the avatar List of modeled joints Head Back (spine on T2) Pelvis Left arm (humerus) Right arm (humerus) Left forearm (radius, cubitus) Right forearm (radius, cubitus) Left hand Right hand Upper left leg (femur) Upper right leg (femur) Lower left leg (tibia, fibula) Lower right leg (tibia, fibula) Left foot Right foot Neck Back (axis: pelvis-vertebral segment T2) Left shoulder Right shoulder Left elbow Right elbow Left wrist Right wrist Left hip (axis: pelvis-upper left leg) Right hip (axis: pelvis-upper right leg) Left knee Right knee Left ankle Right ankle 3

4 SECTION I ❷ Recommended Sensor Placement Guidelines A set of sensor placement recommendations for measuring joint angles within the model have been developed to capture the largest possible range of orientation changes associated with typical movements. Users are free to deviate from these recommendations for optimizing specific needs. Sensors not assigned to the skeletal model will record EMG biofeedback data and orientation information, but not play a role in driving the avatar. The exact placement of Trigno IM sensors will depend on specific User needs. Collecting high-quality EMG biofeedback data generally involves placing the sensor over the belly of the target muscle to avoid innervation zones, tendons, and crosstalk from nearby muscles. Joint angle measurements depend on the orientation of the IM sensor relative to the underlying segment and other sensors. When using Trigno IM sensors for both EMG and inertial measurements, sensor locations should be carefully considered. As an example consider one sensor designated to collect high-quality EMG data from the forearm extensors, placed over the belly of the muscles. A second sensor designated to measure the internal and external rotation of the forearm might be placed distally near the wrist, in order to maximize its movement relative to the elbow. Employing a single sensor to measure both forearm extensor EMG activity and forearm rotation requires choosing between these two locations. Using 2 sensors for this task would produce improved results. 1. HEAD The Trigno IM sensor may be placed on the subject s head in the following locations: 2. ARMS Front of the head Back of the head Either side of the head Depending on which angles are to be estimated, either two or three Trigno IM sensors can be used to model a single arm. The model can estimate the wrist and elbow angles. To estimate both simultaneously, use three sensors at the locations specified below: DELSYS 4

5 SECTION I ELBOW estimates require sensors to be placed on the forearm and humerus. Forearm Place on the top (posterior) of the forearm, as close to the wrist as possible. Humerus Place the sensor facing outwards (laterally) and at mid-length. WRIST estimates require sensors to be placed on the forearm and the hand. Forearm Place on the top (posterior) of the forearm, as close to the wrist as possible. Hand Place on top (dorsal side) of the hand and center the sensor in the middle of the hand. 3. BACK The Trigno IM sensor for the back should be positioned such that the sensor is parallel to the subject s coronal plane, at the T3-T4 level. Make sure the arrow on the front of the sensor is aligned with the spine. Always place a sensor on the back; without it the avatar arms and legs may behave unpredictably. 4. PELVIS The Trigno IM sensor for the pelvis should be positioned such that the sensor is parallel to the subject s coronal plane and centered above the sacrum (L4). 5. LEGS Depending on which angles are to be estimated, either two or three Trigno IM sensors can be used to model a single leg. The model can estimate knee and ankle angles. For estimating both simultaneously, use three sensors at the locations specified below. KNEE estimates require sensors to be placed on the upper leg and lower leg. Upper leg Place on the thigh, above the lateral epicondyle of the knee with the sensor parallel to the sagittal plane. Lower leg Place near the lateral malleolus (above the ankle), with the sensor parallel to the sagittal plane. 5

6 SECTION I ANKLE estimates require sensors to be placed on the lower leg and foot. Lower leg Place near the lateral malleolus (above the ankle), with the sensor parallel to the sagittal plane Foot Place on top of the foot and center the sensor. ❸ Angle Estimations The following section lists the body segments that need to be tracked to estimate each joint angle. Angle Neck Back Shoulder Elbow Wrist Hip Knee Ankle Required Body Segments Head, Back Back, Hip Back, Humerus Humerus, Forearm Forearm, Hand Hip, Upper Leg Upper Leg, Lower Leg Lower Leg, Foot DELSYS 6

7 SECTION I ❹ Guidelines for Data Collection Back Sensor The sensor assigned to the upper back plays a key role in stabilizing the avatar. It affects both upper and lower limb segments. Care should be taken to follow the recommendations stated above so that the left and right side segments are properly anchored to the overall model. Unexpected avatar behavior could indicate that the back sensor location needs to be adjusted. Magnetic Interference Trigno IM sensors include a magnetometer, which may be affected by nearby sources of magnetic and EM interference (e.g., ferrous metals, computers, and cell phones). This interference could adversely affect the Trigno IM orientation estimates. Optimal performance is achieved in the absence of magnetic interference. Try to avoid sources of magnetic inference, especially during sensor calibration. 7

8 EMMA Data Acquisition & Analysis SECTION II ❶ Test Configuration Creating a New Project Open the EMMA software, and make note of the tabs at the top of the window. The File tab contains project management commands, as well as the video import command. To build a new test configuration, click on New under the File tab. The New Project window will open, prompting you to name and describe your test. The Author field will populate automatically with the name attached to the EMMA license. A file location where new project will be saved can be selected. When you have filled in the appropriate information, select Validate. Setting Up for Data Collection After creating a new project or opening a saved project, click on the clock icon to access the Delsys measurement tool. Click on the Trigno System icon, and a configuration window will appear: DELSYS 8

9 SECTION II Each paired Trigno IM sensor is numbered according to its pairing location in the Trigno Control Utility. Sensor data can be selected as either Quaternions or Raw from the drop-down who want orientation data and the ability to estimate angles, make sure that Quaternions is selected. Raw data cannot be collected when Quaternions is selected, and vice-versa. Sensor outputs are listed beneath each sensor; one EMG channel, and either four quaternion channels or nine raw data channels. A graphic below indicates the current orientation of the selected sensor. Preview the signals and orientation of each sensor by selecting a sensor from the drop-down menu. Select Next, and the sensor assignment screen will appear under the Delsys tab: 9

10 SECTION II Sensor Location Drag and drop each Trigno IM sensor (labeled by sensor number) to the appropriate location on the sensor assignment model. Affix each sensor to the corresponding location on the subject. After assigning the sensors to the model, a skeleton avatar will appear in the preview window. This avatar will stream data from each sensor as they are affixed to the subject, and may move strangely during this period. Starting Pose Once all sensors are assigned to the avatar and all sensors are affixed to the subject, the subject should adopt the starting pose demonstrated by the avatar in the above image: Feet hip-width apart Arms by the subject's side, with palms facing in Looking straight ahead Standing straight up Click Zero, and the avatar should snap into the same standing pose as the subject. If not, redo the process until the avatar s pose mirrors the subject s pose. DELSYS 10

11 SECTION II ❷ Data Collection Now that all Trigno IM sensors are calibrated, assigned, and affixed to the subject, the software and system are ready to begin collecting synchronous EMG and movement data. Select Recording mode from the Real Time Recording window. Data collection will begin once you select Start. Data collection is indicated by a timer with a blinking red circle superimposed on the Start button. Real-time EMG channels will also be visible. To end data collection, click Stop. The recording will be documented in the Data window on the left side of the EMMA workspace. Save your project by clicking File, then Save or Save does not automatically save after data collection. ❸ Data Visualization & Analysis Every data collection is saved in the EMMA workspace as a Recording. In each recording, data channels are listed under Measurements, and the avatar is listed under Avatar. Left-clicking on any data channel in the Recording section will populate the visualization window with subplots of traces from each data channel. Traces can be toggled on and off by right-clicking the corresponding data channel and selecting Activate/Deactivate. Certain features of the trace (including name, color, and description. ) can be adjusted by clicking Properties. The avatar recording can be visualized in the lower-left corner of the workspace. Playback can be accelerated or slowed by adjusting the slider bar below the avatr. 11

12 SECTION II Joint Angles EMMA can estimate joint angles from collected orientation data. Click Tools, then Avatar to bring up the analysis tools window. The Avatar tab will display the Trigno IM sensor locations assigned before data collection. The Angle tab offers the options of estimating joint angles, joint angular velocity, and joint angular available joint selections are determined by the Trigno IM sensor location assignments on the model. Once the desired joint estimations are selected, click Calculate. The outputs will be listed as new data channels under Measurements, and can be plotted alongside collected data channels. ❹ Data Import & Export EMMA includes tools to import videos and export project data. Import and export tools can be found under the File tab. Video Import Video files can be associated with EMMA projects, allowing them to be synchronized DELSYS 12

13 SECTION II and played back with data files. Users can record videos of subjects during data collection, then pair those videos with the collected biofeedback data. Click Video, then choose the video file you wish to associate with your project. The Video Import tool will appear, allowing you to adjust the resolution, orientation, and start & end times of the chosen video file. Click Import, name your video, and click OK to import the video file into EMMA. Once the video is imported, you must synchronize the beginning of the video with a time from the data files. EMMA automatically places the Video synchronization and Time curves windows next to one another, making this process easier. Select a time from the Time curves window by clicking on any of the traces. The current time selection is indicated by the vertical red bar; when synchronized, the video file will begin playing at this point. Once the time has been selected, click Link in the Video synchronization window. The selected time will appear in the list, with a lock icon next to it. Click Synchronize when satisfied. The video is now associated to the project, and will play back at the selected time in the data files. Data Export The data contained in an EMMA project, including raw data and joint angle estimates, can be exported as a CSV file for analysis in other software programs such 13

14 SECTION II as EMGworks or MATLAB. Click on the Export Data button at the top of the project screen to bring up the export file window. The export file window lists all data files in the current EMMA project. Use the checkboxes on the right to select which files you wish to export; you can select all files by clicking the checkbox next to Measurements at the top. The oversampling options at the bottom of the window allow exported data files to be resampled. Oversample data at the highest frequency will upsample all data files to match the highest native sampling rate. Oversample data at the lowest frequency will resample all data files to match the lowest native sampling rate. Oversample data at custom frequency will resample all data files to match a custom sampling rate. Raw data with their own frequency will export all data files at their native sampling rates. Selecting Add a header will add header information on each exported data file, including name, start time, sampling rate, and unit of measurement. Add the Time- Code will timestamp each sample, but is only available when all data files have the same sampling rate. DELSYS 14

15 DELSYS, INC. 23 Strathmore Road Natick, MA T F delsys@delsys.com 15